Device for grinding eccentricity in pistons



Feb.6,194o. Y EDWIN E1- AL' 2,189,242

DEVICE FOR GRINDING ECCENTRICITY IN PISTONS Filed March 2, 1939 nur."

\ y INVENToRs SQ/c 50W/N,

i j lsatentetlFeh. 6, 1940 v 0' piston in the usual grinding head.4 1

4This invention Irelates 'itofa cam-grinding pistons. "i'he pisflqlwlautomotive engines are ground vto anevai `shape to accommodate theIunequalfxexpansiondue toi Toneaxis than on the othergtofproduce `an ovalf. s hapeof the old'cylinderis-.

` shape whinlwiunt thel newfpistpntethe'ovei f YOther objects of theinvention are; toprrovii'ie device of this character which can' `befadjusted there 'will be `no lostjmotion o'r looseness ever in thepresent grinding equipment Other 'objects and advantages'resid thejdetail constructionof the'inventiomjwhiclifis de` 3bsignedforsimplicity, economy.` and!eiiiciency; l These willhecornefmore'apparent fromthe fol-" lowing description. i

invention reference is had toV theaccomipnying drawing and throughoutthe description. Inthe'drawlng: Fig. 1 illustrates the inventioninvention. t

Fig. a is e cross-seetibn therethrough. teren en es piston is vindicatedat n with its head u, wrist fichu- 40) A ffpin opening at modern #marked.012" `sertedin the centerpunch socket of the piston Fig. 21s an innerface view of oneffornxfof thefj the lathe or grinding machine withconical, lcounter-sunk center `punch `socket in` the head I4 `intofwhichthe jpint of the dead"centen` j the forward faceof the :disc i6 autapered9 center point I 9` is" forxnedpat the *enact center: 1

g of the disc and ring. center .socket 120 is'` in-` 'jdented inthe rear.facelof the ring to oneside *oitheQcenter ofthe ldisc" and ring. Theamount of eccentricity ofthe sooketnfis g equal toom-half th'ediiierencedesired between` l 'orthecenter punch hole in any-given piston50j? 25during the'erindingA operation; and to provide a device whichwiu requireno changes what@ the long* and short diameters" of fthe? finished each`being "marled for its oii'set asshownatfll'. The: outer face" of ieachiAdisc Ycontaii'is "a gauge toprojectfronrthe frontfacethereof. u

Let `us assume it is desired?` to cistrfnlgrind4 a piston `for 1.012eccentricity."v` gauge line t 2l is scribed across the 'headfI'Lexactlyover'the .axispf thefwristrpin ope'ning.` Thedevce is` selectedand itspcintl is in- A'nowr screwed towarathe pisi'zcmhehd` uhm itrestsA nrmly thereagainsa but not sufliciently far to device 1fromniovingisidewavs onxthefpiston and piston head.

The piston and lthefdevice are no wfinserted s in `the dead center inthe socket 20 ofthe disc; thegauge line 22 on Vthe disc is turnedu intoalignment with the gauge line 24 on the piston; a piece of. shim stock25 is inserted betweenfthe chuck l0 and the piston skirt on the side `ofthe piston to which the dead center is eccentric; and the tail stock istightened. This positions the piston tojone ist` side of the grindingmachine center as indicated 5 the uneven heating 0f the piston. "I'hisallows a `(center or chuck f orturning `or grinding opera 5 t l muchcloser t to be made ofthe pistons withoutV ,tions. l

f danger Vseizing when hot. ljhe usual nisi'firi `v This' inventionVconsistent e device whichmayl grinding machine is designed to grindpistons to.; be `placed between: the `pistn 'head fuwadtha cylindricalshape and cannot impart 'ovi `\l dea'dcenter I2 to oii'setthlatter'froni thecenter 1Q f Shape iilleretu. "1 Punch socket in ther"head tocause the piston to` 10 i The principal `object of lthisLinvention Lis `swing or gyrate about itstrue centenas itfoprovidean`accurate device whichcanfbe placed fates beforejthe grinding "wheelerthe grinder. f n a pistn ingtheus'ual grinding '"iiriachiiiel t0.Y Thedevice Veonsist'szfof afcirciuarlf^disc*'|t"=vvith cause the piston torotate eccentricallysqfjthat 1a threaded peripheryI'ljuponwhichathreaded, t l5 r.the piston may bejground. tolesserjdiameter split, demping ring n is tm-eaddu .i `15 piston. A setof :devices of diiieringoii'sets will i be provid'ed to` 4Suitthedesired conditions,`

ine 22"acros`s9itsi'ace drawn: at right angles to' lift thejpoint I8fronitsseatiinithe pistonicenter 49 punch socket. This adiustmentprevents: the

' also prevents it from rocking ortiltingon the` by the asset eenter11neeAendB"in ne. 1.

the disc kishollowed Vreceive a ,threaded ter axis ci thepoint.

side of the piston.

'Grinding` is now commenced, the major portion of the metal being takenfrom the eccentric Upon completion of this side the tail stockiisloosened and the device is given a one-halfv turn to bring the gaugelines again into alignment with the center socket onjthe opposite side,the

@with eachother; and a shim 'is changed to grinding is repeated piston.

the opposite` side and, the

' It has beenffound that the Irictional engage-vr andthe piston head ison a center point comprising:V a disc; a projectment between thek deviceordinarily suiilcient to position,Y The set screw 23 however is providedto insure the set position; If this' screw beY tightened'after thepiston is in position in the grinder its point will engage relativemovement between the device andthe piston.

the piston head'to prevent innige. 5,*6, and

21 is'threaded,` and uponwhich, a

device. In this form, however, the outer iace of vand internallythreaded to center point 278. .into the outer'iace oi*A the vbutton onVthe center of kthe button.

3 2 by means oiwhich the ftenen of the button 2a. when of Fig. v.'7, thesocket'isfat its yeccentricity. When yrotated one-half turn fromVV 4Ysired to be understood that the samefmay be varied. within the scope-otthe appendedv claims,

' tion.

lsinscribed across the button the disc 26 at .each

The second form of the device is used similarlyv to the `first form. lInthis form, however, the amount of eccentricity may that position thesocket 30 becomes concentric While specific Aforms of the improvementhave been described .and-illustrated herein itis de without departingiromvthe spirit of the invenj Having claimed and desired secured thusdescribed the invention; tenet is by Letters Patent is: l .Y 1. A deviceior supporting workeccentrically on a center-point comprising: a disc; aprojecting point lonone face of said disc for engaging the work; asocket on the other face of the disc for engagement with the centerpoint, said` point and said socket being out of axial alignment with thework; a socket vfor engagement with for the oppositeV` side of the holdit p roper adjusted 7, an alternate form of there'.

.7 device isshown consisting of a disc upon which 1 sa. split ringreenter point V28 is formed. similarto the previous button 29 whichistightly threaded therelnf The hollow in the disc is eccentric of thedisc Vcenter and eccentric ofY the A center socket 30 is .drilled Y 28and disc 26 which, et

. course, places the socket 4toone side oiethe cen- The disc 26 isprovided Vwith -wrench openingsil `and the button is provided j Awithwrench openings Y ing point onfone face through the center i socket 38on theaxisoffgreatesteccentricity ofv ythe latterand gaugelines 34 areinscribed on be regulated by Vro- Y in the positionY point ci lgreatestaisama 2. A device for supporting work eccentrically on a center pointcomprising: a disc; a projecting .point on one ace of said disc forengaging on the other face of the disc the center point, said point andrsaid socket being out of axial alignment peripheral rim member aboutsaidvdisc, the projection of said rim member beyond the face of the discand about said projecting point being adjustable. 1 4

3.-A device ior supporting work eccentrically ing point on one face ofsaid disc for engaging the work; a socket on the outer face of the discfoi-engagement with-the center point, said point said disc, theprojection of saidrim member beyond the face of Vthedisc and about saidprojecting point being adjustable; and means for preventing relativemovement between said device .andsaid work.

j 4. A device for supporting work eccentrically on a center pointcomprising: a disc; a project- Ting point on one face of said Adisc forengaging the'work; fa hollow'in the other face of said'disc,

' said hollow being eccentric of vthe center of. said disc andy saidprojecting point; a button -iitted intosaid hollow; a* socket in theouter face of said button Aforv engagement with the' center point, said'socket being eccentric with said projecting point.

l5. A device for supporting work eccentrically on na center point'comprising: a disc; a projectof said disc for 'engaging the work;Y ahollow in the other face of said disc, said hollow being eccentric ofthe center of said disc andi said ,projecting point; a button fitted ofsaidfbutton for engagement with the center point, said socket beingeccentric withs'ail profjecting point; 1 about said disc,

Vber beyond the face ofY said disc'and about the Vand a peripheral rimVmember the projection of said rimmem'- p iojecting'- point beingadjustable.

6 A device for supporting work eccentrically on a center pointcomprising: a disc; a projecting point on one face of saidjdisc. forengaging the work; a hollow in the other faceof said disc,

saidehollow beingeccentiic oi Vthe center of said disc and saidprojectingpointya buttoniittedV into. .said hollow;.a socket in theouter face of said button for engagement with the center point,

-said socket being eccentric with said projectingd '-point; and la"peripheral rimmemberY aboutsaid ao-l into said hollow'i a'socket in theouter ,face axis of greatest eccentricity of the button socket in thedisc. Y s

disc, the projection of saidzrim member beyond the face of said disc andabout the projecting point being adjustable;v and means for relativelyrotating said button and said disc `to adjust the degree ofYeccentricity between said socket and said projecting point.

e a s ERIC EDWIN.

MERLE PlElTEl'tSON. u

